This invention relates generally to an automotive framing apparatus for performing operations such as positively locating portions of an automotive vehicle being assembled in an assembly line process.
It is known for an automotive framing apparatus or framing station to include a rectangular support frame that includes front and rear pairs of vertical corner posts or pillars and horizontal cross beams that define a frame roof. Carriages serially transport vehicle bodies along a vehicle path that passes under the frame roof and between the front and rear pairs of corner posts. Such an automotive framing apparatus may also include gate assemblies that close around a vehicle body and carry a plurality of tool fixtures that support tools such as clamps and locator pins in positions to engage a vehicle body positioned within the support frame. The tools are commonly used to positively locate and stabilize portions of the vehicle body and/or frame to improve the accuracy of robotic welding operations. Some framing stations are also known to be rapidly adaptable to different vehicle body configurations by interchanging gate assemblies. The ability of an automotive framing apparatus to flexibly adapt to various vehicle body configurations is extremely important to automobile manufacturers.
One such framing system is disclosed in U.S. Pat. No. 5,313,695 issued May 24, 1994 to Negre et al. The Negre et al. patent discloses a framing station that includes a rectangular support frame. The support frame includes horizontal crossbeams that define a frame roof under which vehicle bodies are carried by an assembly line carriage system. The Negre et al. framing station includes four gate assemblies supported in two diametrically opposed gate assembly pairs on the frame roof for rotational movement around a common vertical axis and pivotal movement about respective horizontal axes between a stowed position and a working position. A rotary drive is operatively connected to the gate assemblies and rotates the gate assembly pairs around the common vertical axis between an idle position aligned with the vehicle path and a framing position transverse to the vehicle path when the gate assemblies are in their respective stowed positions. The rotary drive selectively positions one of the two gate assembly pairs at a time in the framing position where the two gate assemblies of the selected gate assembly pair can be pivoted downward to their respective working positions. A pivot drive is also operatively connected to the gate assemblies and rotates the gate assemblies of the selected gate assembly pair between their respective stowed and working positions on either side of a vehicle body to be welded. A plurality of tool fixtures are supported on each gate assembly and support tools in positions to secure a vehicle body positioned within the support frame when the gate assemblies are in their respective working positions. The fixture positioning for each gate assembly pair is adapted to accommodate a specific corresponding vehicle body type. This allows an operator to rapidly convert the apparatus between two different configurations required to perform welding operations on two different vehicle body types. The conversion is accomplished by first upwardly pivoting the gate assemblies of a previously selected gate assembly pair to their respective stowed positions. The gate assemblies of a newly selected gate assembly pair are then rotated into the framing position and are pivoted downward to their respective working positions.
Another example of such a framing system is disclosed in U.S. Pat. No. 4,670,961 issued Jun. 9, 1987 to Fontaine et al. The Fontaine et al. patent discloses a front rotary gate assembly magazine suspended from a support frame roof above a vehicle path and supporting four front gate assemblies for rotation about a front vertical axis and for pivotal motion about respective horizontal axes. Each of the front gate assemblies is selectively rotatable to a front framing position and, from the front framing position is downwardly pivotable to a working position to service a front region of a vehicle body positioned beneath the support frame roof. A rear rotary gate assembly magazine is also suspended from a support frame roof above a vehicle path and supports four rear gate assemblies for rotation about a rear vertical axis and for pivotal motion about respective horizontal axes. Each of the rear gate assemblies is selectively rotatable to a rear framing position and, from the rear framing position is downwardly pivotable to a working position to service a rear region of a vehicle body positioned beneath the support frame roof.
However, the gate assemblies of the Negre et al. and Fontaine et al. framing stations are supported beneath their respective frame roofs. Therefore, the frames must be tall enough to suspend the gate assemblies in positions where they will not interfere with vehicle bodies as they pass through the framing stations. In addition, the corner posts must be set far enough apart, and therefore, the frame footprints must be broad enough so that the gate assemblies will clear the corner posts when rotating in their respective stowed positions.
An automotive framing apparatus is provided that includes a support frame having a frame roof supported above a generally horizontal support surface. At least four gate assemblies are supported in a circumferentially-spaced array on the frame roof for rotational movement around a common vertical axis. The four gate assemblies form two pairs of diametrically-opposed gate assemblies. The gate assemblies of each gate assembly pair are supported for pivotal movement between respective diametrically-opposed stowed and working positions about respective horizontal axes. A rotary drive is operatively connected to the gate assemblies and is configured to rotate the gate assemblies around the common vertical axis when the gate assemblies are in their respective stowed positions. The rotary drive rotates the gate assemblies between an idle position aligned with the vehicle path and a framing position transverse to the vehicle path. The rotary drive is configured to selectively position one gate pair at a time in the framing position from which the two gate assemblies of the selected gate assembly pair can be pivoted downward to respective diametrically opposed working positions on either side of a vehicle body to be welded. A pivot drive is operatively connected to the gate assemblies and is configured to pivot the gate assemblies of the selected gate assembly pair between their respective stowed and working positions. Tool fixtures are supported on the gate assemblies and are configured to support tools in positions to perform operations on a vehicle body positioned under the frame roof when the gate assemblies supporting the tool fixtures are in their respective working positions. Each gate assembly pair supports tool fixtures positioned to allow tools to perform operations on a specific corresponding vehicle body type. This allows the apparatus to quickly convert between two different tooling configurations as required to perform operations on two different vehicle body types.
The automotive framing apparatus also includes a rotary carrousel supported on the frame roof for rotation around the common vertical axis. The gate assemblies are pivotally supported on the rotary carrousel and are disposed above the frame roof when in their respective stowed positions. Because the gate assemblies rotate above the frame roof, the lateral dimensions of the support frame can be smaller than the diametrical reach of the gate assembly pairs in their stowed positions. Positioning the gate assemblies above the support frame also allows the height of the support frame to be less than would be required to suspend the carrousel and gate assemblies below the frame roof. Therefore, an automotive framing apparatus constructed according to the invention is able to flexibly adapt to different vehicle body configurations in an assembly line process while requiring a smaller support frame footprint and smaller vertical support frame dimensions than existing systems.
The invention also includes a method for using the framing apparatus to perform framing operations on an automotive vehicle body in an assembly line process. According to this method, after performing operations on one or more vehicle bodies of a first configuration, one can flexibly adapt the automotive framing apparatus to perform operations on one or more vehicle bodies of a second configuration. This is done by first pivoting the gate assemblies of a previously selected gate assembly pair upward to their respective stowed positions. The gate assemblies of the newly selected gate assembly pair are then rotated around the common vertical axis into the framing position and are downwardly pivoted to their respective working positions. The tools supported on the newly selected gate assembly pair are then actuated to perform operations on a vehicle body of the second configuration that is disposed on the vehicle path between the gate assemblies.
Objects, features and advantages of this invention include the ability to flexibly service up to three different vehicle body configurations on a single assembly line, to reduce friction between gate assemblies and structures that support them, to smoothly convert vertical reciprocal ram motion into arcuate reciprocal gate assembly motion, to allow an operator to install gate portions configured to perform operations on different body types, to more positively locate portions of a vehicle body in proper relative positions for welding, to improve weld accuracy through improved gate assembly stabilization, to allow vehicles bodies of like configuration to be sequenced through the framing apparatus without having to lift the gate assemblies to their stowed positions, and to significantly reduce the amount of energy required to drive gate assemblies and the amount of wear on associated machinery.